In a large mixing bowl, toss the pumpkin with 2 tablespoons olive oil and 1 teaspoon of the salt.

In a large, heavy pot or Dutch oven , melt the butter with 2 tablespoons olive oil over medium-high heat. Add the pumpkin mixture, onions , leek , bay leaves , the remaining teaspoon of salt, the white pepper , and sugar. Cook, stirring, until the onions are soft and lightly golden, 8 to 10 minutes. Add the chicken broth , diced roasted pumpkin, herbs and wine . Stir to mix. Bring to a boil, and then reduce the heat to medium and cook, uncovered, for 20 to 25 minutes, or until pumpkin is tender and broth is just beginning to thicken slightly. Once the pumpkin is tender, puree the soup using an immersion blender .

In a medium saute pan, brown the sausage. Using a slotted spoon remove the sausage from the pan and drain on paper towel. Add the sausage to the soup and simmer another 10 minutes.

Remove the bay leaves and herb sprigs and discard. Garnish the soup with the cheese and serve with warm crusty bread.